1. Field of the Invention
The present invention relates to bulked continuous filament (BCF) bundled yarns, and, more particularly, to bulked continuous filament bundled yarns made from differently colored singles yarns wherein the bundled yarns are capable of providing space-dyed effects in tufted floor coverings.
2. Description of Related Art
As used herein, certain terms have the meanings ascribed to them as follows:
The terms xe2x80x9cthreadxe2x80x9d and xe2x80x9cfilamentxe2x80x9d are intended to connote single filament fibers, whereas xe2x80x9csingles yarnxe2x80x9d or xe2x80x9cstrandxe2x80x9d is an assembly of two or more threads or filaments.
The term xe2x80x9cnodexe2x80x9d is intended to mean relatively compact, tangled sections of a yarn that are separated by relatively bulky or unentangled sections.
The term xe2x80x9centanglingxe2x80x9d is intended to mean the mixing of fiber components to an extent that the individual components cohere to one another, where xe2x80x9ccoherexe2x80x9d means to stick or hold together in a visually identifiable and distinguishable mass, an example of which is the above-mentioned xe2x80x9cnodexe2x80x9d. Entangling includes directing a flow of fluid, such as air, against a moving plurality of strands transversely of the direction of movement of the strands. The resulting dislocation of the strands leads to a knot-like intertwining and entangling of the strands. The term xe2x80x9cair-jet entanglerxe2x80x9d is a device which achieves an entangled yarn by co-mingling the components of the yarn.
A xe2x80x9ctexturing processxe2x80x9d causes a permanent departure from the original longitudinal shape of the filament, for example, by causing the filament to be crimped, or to have some degree of curved or angular change along its length. One example of a texturing process employs a chamber in which a yarn is moved at high speed through a flow of heated gas or vapor, i.e., hot air or steam. Alternatively, heated or unheated yarn may be moved at high speed through a mechanical crimping process. In either arrangement, the fiber is then bulked by collision with a surface which, for practical purposes, may be the wad or plug formed by the yarn itself. As a consequence, individual yarns deposit themselves in a regularly bent configuration on an impact surface, and because of heat-induced effects, the yarns to some degree retain this curved or angular configuration. In the embodiment in which the fiber is heated with air, the crimped fiber configuration is made permanent by a cooling process, without permitting portions of the yarn to adhere, or be connected, to each other.
Singles yarns may be combined into plied yarns in several ways that usually involve the use of texturing of filaments followed by air-jet entangling. For example, three separate singles yarns can be combined into a final BCF product. The process may be a xe2x80x9cone-stepxe2x80x9d or xe2x80x9ctwo-stepxe2x80x9d process. The one-step process begins with forming the spun filaments making up the yarns and continues through all subsequent steps to winding of the final product, without interim spooling. In known two-step processes, the spun yarns are wound up after the first step of spinning, drawing, and texturing. The second step typically involves unwinding the yarn from a storage spool, which includes precision tension control before commencing the entangling step.
Both the one-step and two-step processes often employ a number of known steps, however, various permutations of those steps, together with uniquely selected parameter settings, determine which of a wide variety of results are achieved, in terms of filament and yarn configuration, and/or in terms of the appearance and performance of the ultimate product produced using such yarns. A specific sequence of process steps, along with a corresponding selection of process parameters, such as temperature, yarn tension, and other particulars, can determine a unique and possibly unforeseeable result, in terms of yarn specifications and functional and appearance qualities of a carpet made from the yarn.
One particular BCF yarn product is a space-dyed yarn, which has repeated, random or regular, intense bands of different colors along its length, which provide unique accent styling, primarily, but not exclusively, in tufted floor coverings, such as carpets. Such carpet products are normally manufactured by post-coloring of uncolored spun yarns with dyestuffs in an intermittent, regular or random, fashion. The yarns are then (ply)twisted and heat set. An example of such methods may be found in U.S. Pat. No. 4,153,961. Such yarns, when fully processed into carpet face yarns, exhibit pinpoints or larger xe2x80x9cpixelsxe2x80x9d of different colors against a more mixed background shading. Depending on the regularity of spacing between colors, and the length of the different colors present in the yarns, the carpet can also feature a wider repeat patterning of areas of single perceived shade and areas of pinpoints of bright colors against a background of the single perceived shade.
Such effects are, to a large extent, different from those achieved with so-called xe2x80x9cheatherxe2x80x9d yarns. Heather yarns, while also containing different colors, are mixed in such a way during processing that no one color predominates, and a single shade is perceived in carpeting made from such yarns, except on very close inspection. A heather appearance includes small points of individual color, i.e., color points, randomly distributed throughout a matrix of contrasting colors. In contrast to processes for making space-dyed yarn products, processes for making heather yarns are formulated to prevent the formation of any directional carpet appearance or patterns, such as streaks and chevrons in the finished product.
In order to eliminate the complex dyeing processes used to manufacture xe2x80x9ctruexe2x80x9d space-dyed yarns, attempts have been made to utilize yarns which have been pre-colored in single colors, either by dyeing or by melt pigmentation. Such pre-colored singles yarns have been combined, in groups of two or more, with at least one group being of a different color than the others, to provide final yarns with a variety of coloring effects. The specific sequence of the process steps is as important as the selected steps, themselves. Such yarn products are referred to as xe2x80x9capparent space-dyed yarnsxe2x80x9d as their effects in a tufted product make them appear to be space-dyed yarns.
U.S. Pat. No. 5,804,115 discloses a one-step process for producing an apparent space-dyed yarn, made by sequentially spinning two or more strands having two or more colors, forming two or more yarn fractions from the strands, independently texturing and entangling at least one of the yarn fractions, and then together entangling all of the yarn fractions. This arrangement suffers from restrictions on process control flexibility, because it is performed as a one-step process. In a one-step process, fibers are spun at a minimum viable rate, e.g., 500 m/min., which, at a conventional 3:1 draw ratio, results in a downstream feed rate of 1500 m/min. At this rate, a desired level of precision in the downstream processing, in particular, in the air-jet entangling, cannot be attained. As a result, the space-dye effect of the yarn product when tufted into carpet is not as pronounced or as crisp as it otherwise might be.
The above process and products are, to varying degrees, unsatisfactory in terms of complexity, and/or their inability to provide the range of effects required to simulate true space-dyed yarns. Thus, there remains a need for a process for producing a simple, effective, product yarn series which can match all of the effects possible using true space-dyed yarns, and to produce other unique effects not possible by other means.
The present invention provides a process for combining a plurality of single color feed yarns, either dyed or melt pigmented, without twisting or heat-setting, to form an apparent space-dyed yarn product which closely approaches the aesthetic and design requirements of a true space-dyed yarn. Advantageously, the process preferably uses melt pigmented, also known as solution-dyed, singles yarns, which have been found to offer superior end-use performance, e.g., low color fade, and resistance to harsh cleaning methods.
The present invention includes a process for making apparent space-dyed bulked continuous filament yarn employing the sequential steps of: (a) individually and simultaneously drawing two or more pre-spun, pre-colored singles yarns, at least one of which is differentially colored with respect to the other yarns; (b) individually and simultaneously texturing the two or more yarns; (c) individually and simultaneously air-jet entangling the two or more textured yarns in a first air-jet entangling process to form respective two or more entangle-sequenced yarns each having fiber portions having segments of entangled and unentangled fibers; (d) together air-jet entangling the two or more segments of entangled and unentangled fiber yarns in a second air-jet entangling process to form a final apparent space-dyed yarn; and (e) winding up the final apparent space-dyed yarn.
The texturing step involves mechanically crimping the yarn by moving the yarn at high speed through frictional rolls pressed together, thereby forming a rectilinear, two dimensional zig-zag pattern. Alternatively, the yarn may be moved through a flow of heated gas or vapor, i.e., hot air or steam, to form a curvilinear profile, after which the yarn is bulked by collision with a surface which, for practical purposes, may be the wad or plug formed by the strand itself.
The first air-jet entangling step includes, for each singles yarn, a respective, individual entangler, which is arranged to provide pre-determined patterns of on-off cycles of pressurized air through jets, which results in segments of entangled and unentangled fibers in the respective singles yarn. Each individual jet in the first entangling process operates on the same, or optionally, on a different timing sequence as the other jets, and the sequences themselves may be even or uneven, i.e., the time-on interval may be the same as, or different than, the time-off interval.
The second air-jet entangling step employs a further entangler, and the entangling which is carried out on the final, combined yarn, is also programmably controlled, and operates under the same, or, optionally, a different, timing sequence as that of the first set of air-jet entanglers.
According to the present invention, the timing sequence control of the first and second air-jet entangling processes preferably is electronically programmed in such a manner as to controllably entangle the drawn and textured singles yarns in an intermittent, regular or random, fashion. This makes possible the manufacture of a wide range of color effects in the final yarn product. This method for processing multicolored yarn produces a yarn which effectively duplicates all effects possible with traditional space-dyed yarns, and does so with a limited palette of colors. Moreover, the process of the invention offers unique styling possibilities not available by any other means.
Other aspects of the yarn processing sequence, including drawing, texturing and winding, utilize equipment and techniques for such processes which are known to those skilled in the art.
Therefore, it is a principal object of the present invention to provide an apparatus and process to produce a yarn product that can duplicate all effects possible with true space-dyed yarns.
A further principal object of the present invention is to provide a process for making apparent space-dyed yarn that features sequences of xe2x80x9cheatherxe2x80x9d type mixed color, along with sequences where selected colors are each separately visible on turning the yarn, whereby, when tufted into a carpet, the perceived color effect is comparable to that provided by true space-dyed yarns in such carpet products.
It is a further object to provide a process for making apparent space-dyed yarn which can be used to provide a broad range of potential effects, using only a limited palette of colors.
Still another object of the present invention is to provide a process for making apparent space-dyed yarn that offers unique styling possibilities not available by other processing means.
Another object of the present invention is to provide a process for making apparent space-dyed yarn which uses melt pigmented singles yarns.
Another object of the present invention is to provide a process for making a ready-to-tuft apparent space-dyed yarn that does not include the steps of twisting or heat-setting.
Another object of the present invention is to provide a process for making apparent space-dyed yarn wherein the process involves selectable control of node position, frequency, randomness, and tightness.
Other objects and benefits of the present invention will become apparent from the following written description and accompanying figures.